add global flag to define download directory for remote configuration (oci & git)

Signed-off-by: Guillaume Lours <705411+glours@users.noreply.github.com>

Author: glours

cmd/compose/compose.go

@@ -150,6 +150,7 @@ type ProjectOptions struct {
 	Progress      string
 	Offline       bool
 	All           bool
+	DownloadDir   string
 }
 
 // ProjectFunc does stuff within a types.Project
@@ -226,7 +227,9 @@ func (o *ProjectOptions) addProjectFlags(f *pflag.FlagSet) {
 	f.BoolVar(&o.Compatibility, "compatibility", false, "Run compose in backward compatibility mode")
 	f.StringVar(&o.Progress, "progress", string(buildkit.AutoMode), fmt.Sprintf(`Set type of progress output (%s)`, strings.Join(printerModes, ", ")))
 	f.BoolVar(&o.All, "all-resources", false, "Include all resources, even those not used by services")
+	f.StringVar(&o.DownloadDir, "download-dir", "", "Directory to store OCI or GIT Compose configurations")
 	_ = f.MarkHidden("workdir")
+	_ = f.MarkHidden("download-dir")
 }
 
 // get default value for a command line flag that is set by a coma-separated value in environment variable
@@ -372,8 +375,8 @@ func (o *ProjectOptions) remoteLoaders(dockerCli command.Cli) []loader.ResourceL
 	if o.Offline {
 		return nil
 	}
-	git := remote.NewGitRemoteLoader(o.Offline)
-	oci := remote.NewOCIRemoteLoader(dockerCli, o.Offline)
+	git := remote.NewGitRemoteLoader(o.Offline, o.DownloadDir)
+	oci := remote.NewOCIRemoteLoader(dockerCli, o.Offline, o.DownloadDir)
 	return []loader.ResourceLoader{git, oci}
 }
 
@@ -537,6 +540,22 @@ func RootCommand(dockerCli command.Cli, backend Backend) *cobra.Command { //noli
 				}
 			}
 
+			if opts.DownloadDir != "" {
+				if len(opts.ConfigPaths) == 0 {
+					return fmt.Errorf("cannot use --download-dir without --file using oci:// or git:// prefix")
+				}
+				remoteResources := false
+				for _, file := range opts.ConfigPaths {
+					if strings.HasPrefix(file, "oci://") || strings.HasPrefix(file, "git://") {
+						remoteResources = true
+						break
+					}
+				}
+				if !remoteResources {
+					return fmt.Errorf("cannot use --download-dir without --file using oci:// or git:// prefix")
+				}
+			}
+
 			composeCmd := cmd
 			for {
 				if composeCmd.Name() == PluginName {

docs/reference/docker_compose.yaml

@@ -102,6 +102,15 @@ options:
       experimentalcli: false
       kubernetes: false
       swarm: false
+    - option: download-dir
+      value_type: string
+      description: Directory to store OCI or GIT Compose configurations
+      deprecated: false
+      hidden: true
+      experimental: false
+      experimentalcli: false
+      kubernetes: false
+      swarm: false
     - option: dry-run
       value_type: bool
       default_value: "false"

internal/paths/paths.go

@@ -118,3 +118,23 @@ func EncompassingPaths(paths []string) []string {
 	}
 	return result
 }
+
+func GetAbsPath(path string) (string, error) {
+	if filepath.IsAbs(path) {
+		return path, nil
+	}
+
+	if strings.HasPrefix(path, "~") {
+		home, err := os.UserHomeDir()
+		if err != nil {
+			return "", err
+		}
+		return filepath.Join(home, path[1:]), nil
+	}
+
+	wd, err := os.Getwd()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(wd, path), nil
+}

pkg/remote/git.go

@@ -25,6 +25,8 @@ import (
 	"regexp"
 	"strconv"
 
+	"github.com/docker/compose/v2/internal/paths"
+
 	"github.com/compose-spec/compose-go/v2/cli"
 	"github.com/compose-spec/compose-go/v2/loader"
 	"github.com/compose-spec/compose-go/v2/types"
@@ -45,16 +47,18 @@ func gitRemoteLoaderEnabled() (bool, error) {
 	return false, nil
 }
 
-func NewGitRemoteLoader(offline bool) loader.ResourceLoader {
+func NewGitRemoteLoader(offline bool, downloadDirectory string) loader.ResourceLoader {
 	return gitRemoteLoader{
-		offline: offline,
-		known:   map[string]string{},
+		offline:           offline,
+		known:             map[string]string{},
+		downloadDirectory: downloadDirectory,
 	}
 }
 
 type gitRemoteLoader struct {
-	offline bool
-	known   map[string]string
+	offline           bool
+	known             map[string]string
+	downloadDirectory string
 }
 
 func (g gitRemoteLoader) Accept(path string) bool {
@@ -89,12 +93,20 @@ func (g gitRemoteLoader) Load(ctx context.Context, path string) (string, error)
 			return "", err
 		}
 
-		cache, err := cacheDir()
-		if err != nil {
-			return "", fmt.Errorf("initializing remote resource cache: %w", err)
+		if local == "" {
+			cache, err := cacheDir()
+			if err != nil {
+				return "", fmt.Errorf("initializing remote resource cache: %w", err)
+			}
+			local = cache
+		} else {
+			local, err = paths.GetAbsPath(g.downloadDirectory)
+			if err != nil {
+				return "", err
+			}
 		}
 
-		local = filepath.Join(cache, ref.Commit)
+		local = filepath.Join(local, ref.Commit)
 		if _, err := os.Stat(local); os.IsNotExist(err) {
 			if g.offline {
 				return "", nil

pkg/remote/oci.go

@@ -31,6 +31,7 @@ import (
 	"github.com/docker/buildx/util/imagetools"
 	"github.com/docker/cli/cli/command"
 	"github.com/docker/compose/v2/internal/ocipush"
+	"github.com/docker/compose/v2/internal/paths"
 	v1 "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
@@ -47,18 +48,20 @@ func ociRemoteLoaderEnabled() (bool, error) {
 	return false, nil
 }
 
-func NewOCIRemoteLoader(dockerCli command.Cli, offline bool) loader.ResourceLoader {
+func NewOCIRemoteLoader(dockerCli command.Cli, offline bool, downloadDirectory string) loader.ResourceLoader {
 	return ociRemoteLoader{
-		dockerCli: dockerCli,
-		offline:   offline,
-		known:     map[string]string{},
+		dockerCli:         dockerCli,
+		offline:           offline,
+		downloadDirectory: downloadDirectory,
+		known:             map[string]string{},
 	}
 }
 
 type ociRemoteLoader struct {
-	dockerCli command.Cli
-	offline   bool
-	known     map[string]string
+	dockerCli         command.Cli
+	offline           bool
+	known             map[string]string
+	downloadDirectory string
 }
 
 const prefix = "oci://"
@@ -98,12 +101,19 @@ func (g ociRemoteLoader) Load(ctx context.Context, path string) (string, error)
 			return "", err
 		}
 
-		cache, err := cacheDir()
-		if err != nil {
-			return "", fmt.Errorf("initializing remote resource cache: %w", err)
+		if local == "" {
+			cache, err := cacheDir()
+			if err != nil {
+				return "", fmt.Errorf("initializing remote resource cache: %w", err)
+			}
+			local = filepath.Join(cache, descriptor.Digest.Hex())
+		} else {
+			local, err = paths.GetAbsPath(g.downloadDirectory)
+			if err != nil {
+				return "", err
+			}
 		}
 
-		local = filepath.Join(cache, descriptor.Digest.Hex())
 		composeFile := filepath.Join(local, "compose.yaml")
 		if _, err = os.Stat(local); os.IsNotExist(err) {
 			var manifest v1.Manifest